sf_blocks
sbp->f_blocks = (int32_t)sfp->sf_blocks;
sbp->sf_blocks = fxdr_unsigned(u_int32_t, *tl++);
sfp->sf_blocks = txdr_unsigned(NFS_V2CLAMP32(sf->f_blocks));
sbp->f_blocks = fxdr_unsigned(int32_t, sfp->sf_blocks);